Compositions which can be used in diluted form are known in the art. In such compositions, the technical problem lies in sustaining upon dilution an efficient cleaning performance. Such compositions for dilute cleaning are described for instance in the European Patent EP-A- 0 503 219. In these compositions, the dilute cleaning performance is obtained by using alkanolamines. This '219 patent application also mentions the use of nonionic surfactants among which ethoxylated fatty alcohols are listed.
Hard surface cleaning compositions comprising various surfactants, including highly ethoxylated nonionic surfactants, which can be used in diluted form are also known in the art. Representative of this prior art are the compositions described in European Patent Application EP 92870045.9.
There is a constant strive for the development of cleaning compositions with better performance in several respects. Better cleaning on all soils, including greasy soils and soap scum is of course a principal object, both for neat and diluted compositions which are often used in the cleaning of for instance hard surfaces. Such greasy soils are commonly brought by cooking with oils and fatty foods, and by simple contact with human skin, thus they are present on most surfaces, particularly in bathrooms and kitchens.
It is thus an object of the present invention to provide cleaning compositions which can be effectively used in diluted form, on various surfaces as well as in laundry applications, to clean various soils and stains. More specifically, it is a further object of the present invention to provide satisfactory shine performance and surface safety when used as hard surface cleaners.
It has now been found that this object can be efficiently met by formulating cleaning compositions comprising a specific nonionic surfactant system. Indeed, it has been found that cleaning compositions comprising at least a first nonionic surfactant with an HLB of at least 12(hydrophilic-lipophilic balance) and at least a second nonionic surfactant with an HLB below 10 and at least 4 less than the HLB of said first surfactant exhibit a great flexibility in the soils it may clean. These compositions unexpectedly exhibit outstanding cleaning performance upon dilution, compared to compositions comprising typical nonionic surfactants while the cleaning performance of the neat, i.e. undiluted compositions is similar, regardless of the presence of said nonionic surfactant system.
In other words, it has now been found that the cleaning compositions comprising a nonionic surfactant system of at least a first surfactant with an HLB of at least 12 and at least a second surfactant with an HLB below 10 and at least 4 less than the HLB of said first surfactant exhibit outstanding cleaning performance when used both neat and diluted.
Specifically, the compositions according to the present invention are especially effective on greasy soils, both when used in hard water and also when used in soft water. Indeed, a particular advantage of the present invention is robustness to different usage conditions, e.g. variations in water hardness used for diluting the product.
This invention is also particularly useful as it allows to formulate compositions with reduced levels of other ingredients, yet retaining optimal cleaning performance, due to said combination of at least a first nonionic surfactant with an HLB of at least 12 and at least a second nonionic surfactant with an HLB below 10 and at least 4 less than the HLB of said first surfactant; also, the user needs less product to achieve the same task. This advantage is particularly valuable in terms of environmental compatibility.